Dr. Onacha is a geothermal exploration, development, and management professional with over 20 years of international experience in the public and private sectors. Dr. Onacha has worked in several countries on geothermal exploration projects including the USA, Iceland, St Kitts, and Nevis, New Zealand, Rwanda, Comoros, and Kenya. Prior to embarking on PhD studies at Duke University, Onacha worked as the Chief Geophysicist and later as the leader in Geothermal Resources Development for the Kenya Electricity Generating Company (KenGen) geothermal project in Kenya. 

His responsibilities included implementing all strategic plans, programs, and scientific activities including the design and implementation of geophysical techniques for the exploration, development, and monitoring of geothermal fields. He also had the responsibility of identifying and locating geothermal exploration, production, injection, and make-up wells. Before joining IESE, Onacha was in charge of all the geothermal resources assessment and development activities in KenGen that culminated in locating high production exploration wells in a new geothermal field using the joint geophysical imaging technique (JGI). The JGI project was sponsored by the United Nations Environmental Programme (UNEP) and the Global Environmental Facility (GEF). He has been the principal investigator on several geothermal exploration projects in Iceland, Kenya, Comoros, and USA.